Large number of methods for compound delivery in a variety of applications such as personal care, health & agricultural applications etc. has been reported. Specifically, in oral care applications, materials that are targeted at teeth enamel, gums, etc. in the oral cavity are often sub optimally used as they get washed out during use. Therefore, materials that are able to carry a payload of antibacterials, active compounds, etc. and that can specifically target areas in the oral cavity or in general the area of application and deliver the payload over a period of time are of great use.
The use of such delivery methods can significantly bring down the amount of antibacterial, active compounds, etc., which are used in current formulations as the desired or even better effects may be achieved in lower amount of required active compound which would be localized and be released over a sustained period of time. This would bring down the costs of the formulations especially in oral care products, where the quantum of the active compound is deliberately kept high considering the sub-optimal use. Further, by continuous delivery of an optimal dose, dangers associated with abrupt release of a high loading of the antibacterial compound are eliminated. The inhibiting costs of such compounds may also call for new methods of delivery.
To achieve these purposes, Polyelectrolyte-surfactant complexes (PSC's) may be one of the many options. PSCs are unique materials with the ability to spontaneously self-assemble into highly ordered nanostructures. PSCs are typically formed by the complex formation of polyelectrolytes and/or oppositely charged ionic surfactants, usually in aqueous solution. Macromolecules with hydrophobic groups as side chains have important applications in many industries and medicine, such as in drug delivery because of their unique associative behavior and special rheological properties. In addition, these polymers can serve as simplified models of natural polyelectrolytes. The interactions of surfactant and hydrophobically modified polymers are considered to be the result of complexes formed between surfactant and polymer due to electrostatic and hydrophobic forces. The presence of intramolecular micelles allows the solubilization of compounds with normally low water solubility. The solubilized compounds can have sizable effects on both intra- and intermolecular interactions. Extensive work has been done in the area to optimize the polymer surfactant complexes for their maximum utilization.
Strauss et. al. in J. Polym. Sci. 1951, 6, 649 have employed the hydrolyzed form of the regularly alternating copolymers of maleic anhydride and alkyl vinyl ethers because of their aggregation behavior in solution. U.S. Ser. No. 10/512,228 discloses a surfactant comprising a triblock copolymer including a hydrophilic block, a charged water-soluble block and a hydrophobic block for gene therapy applications.
U.S. Ser. No. 11/998,981 discloses that, by including a suitable polymer-micelle complex in a spin dope, one can electrospin fibers to include materials that may not otherwise be capable of being electrospun into fibers, either in a particular solvent or in any solvent.
U.S. Pat. No. 5,690,911 discloses an aqueous oral composition comprising an effective amount of halogenated diphenyl ether or phenolic antibacterial compound such as triclosan, a mixture of an anionic surfactant and non-ionic surfactants at a weight ratio of about 14:1 to about 9:1, and anionic polymeric polycarboxylate such as methyl vinyl ether/maleic anhydride copolymer, in an orally acceptable vehicle containing less than 60% by weight water. Further, the anionic surfactant is sodium lauryl sulfate; and the nonionicsurfactant is selected from polyoxyethylenesorbital fatty ester, polyethoxylated glycerol, alkyl glucoside.
Deo et. al in Langmuir 2005, 21, 3950-3956 discloses the study of the interactions of a nonionic surfactant such as penta-ethylene glycol mono n-dodecyl ether (C12EO5), with a hydrophobically modified anionic polymer i.e. poly(maleic acid/octyl vinyl ether) (PMAOVE), in aqueous solutions by involving measurements of surface tension, viscosity, electron paramagnetic resonance (EPR), light scattering, and fluorescence.
US2012087962 discloses a personal care article comprising absorbent, cellulosic substrate impregnated with an impregnation formulation having activity to de-activate pathogenic micro-organisms; the coating comprises an acidic polymer such as Gantrez™ S-96 and Gantrez™ S-97; a surfactant and an organic carboxylic acid such as citric acid. Further, the surfactant comprises an anionic surfactant or non-ionic surfactant selected from the Tween™ such as Tween 20™ or Polysorbate™ family Polysorbate 20™.
The effectiveness of the antibacterial, drugs or bioactive compounds contained in the materials employed in personal care products or oral care products is dependent upon the delivery of antibacterial or bioactive compounds at the areas of application.
According to the reported methods, the materials employed in oral care applications that are targeted at teeth enamel, gums, etc. in the oral cavity are often suboptimally used and they get washed out during its use. Therefore, such materials carrying or containing antibacterials, drug or bioactive compounds do not effectively deliver the antibacterials, drug or bioactive compounds specifically at the areas of the application which leads to the use of excessive amounts of active compounds in the preparation of oral care products or personal care products.
Therefore, there is need in the art to provide a material which would be able to carry a payload of antibacterials, drugs or bioactive compounds and specifically target the areas in the oral cavity, and also would feasibly deliver the antibacterial, drug or bioactive compounds at the area of application in an efficient manner.
To overcome the aforesaid limitations, the present discloses a surfactant-copolymer complex for delivery of hydrophobic compounds such as antibacterials, ointments, drugs, bioactives, perfumes, flavors, pesticides etc., with controlled release; and a viable process for the preparation thereof. Specifically, the present invention shows how careful formulation can be used to create a novel structure comprising of hydrophobic compound-loaded non-ionic micellar structures that complex with a copolymer. The copolymer enables targeting of the complex to specific areas, while the structure of the complex allows for controllable and sustained release of the hydrophobic compound.